I recommend a CoolerMaster AeroGate II or III, you get good control of your fans, and they come with sensors that you can attach on various spots in your computer so you can adjust up and down upon own demand.
I have to agree with above statement though. You might want to utterly clean your fans. my Right side topside fan almost stopped because of alot of dust gathering in it. It stopped several times. So I just opened up and cleaned (2 mins of my time.) And done
Sincerely Yours
Red Hammer